Effect of supplementation with cobalamin carried either by a milk product or a capsule in mildly cobalamin-deficient elderly Dutch persons.

BACKGROUND A high prevalence of cobalamin deficiency occurs in the elderly population, which may be treated orally or with injections. Little is known about the relative bioavailability of crystalline cobalamin added to food products. OBJECTIVE The objective was to assess the effect of supplementation with 1000 microg crystalline cobalamin, carried either by a milk product or a capsule, on cobalamin status in mildly cobalamin-deficient elderly Dutch persons. DESIGN Two double-blind randomized controlled intervention studies, each covering a 12-wk supplementation period, were carried out in parallel. Mildly cobalamin-deficient elderly persons (n = 112) were separately recruited for the milk and capsule trials. Mild cobalamin deficiency was defined as a cobalamin concentration between 100 and 300 pmol/L and a plasma methylmalonic acid (MMA) concentration > or = 0.30 micromol/L. Allocation to the placebo or cobalamin carrier was carried out independently in both trials. RESULTS In the fortified-milk group, the mean (+/-SD) increase in serum cobalamin was 250 +/- 96 pmol/L, the median (5th and 95th percentiles) decrease in plasma MMA was 0.19 (-0.76, -0.04) micromol/L, and the median decrease in plasma homocysteine was 4.0 (-7.3, 3.0) micromol/L. All changes were significantly different from those in the placebo milk group (P < 0.01). Likewise, in the cobalamin-capsule group, the mean increase in serum cobalamin was 281 +/- 136 pmol/L, the median decrease in plasma MMA was 0.18 (-2.95, 0.14) micromol/L, and the median decrease in plasma homocysteine was 1.8 (-10.6, 2.4) micromol/L; all changes were significantly different from those in the placebo capsule group (P < 0.01). No significant differences were observed between the fortified-milk and capsule groups (P > 0.40). CONCLUSION Crystalline cobalamin added to milk is an effective alternative to cobalamin capsules for improving cobalamin status.